1. Field of the Invention
The present invention relates to an apparatus for the conversion of methane to higher boiling hydrocarbons. In particular, the invention relates to a novel baffled reactor having adequate structural strength at elevated reaction temperatures and which is especially adapted for the use of fluidized solid catalyst systems in the conversion of methane to higher molecular weight hydrocarbons.
2. Description of the Prior Art
Methane is found in large quantities in gaseous form in somewhat remote regions of the world. The transportation of this methane to areas where it can be utilized is relatively inefficient.
Considerable work has been carried out relating to the conversion of methane to higher molecular weight hydrocarbons which are readily condensable and which can be conveniently transported in liquid form. In this regard, reference is made to the following U.S. patents which are concerned with conversion of methane to higher hydrocarbons: U.S. Pat. Nos. 4,443,649; 4,444,984; 4,443,648; 4,443,645; 4,443,647; 4,443,644; 4,443,646; 4,499,323; 4,499,324; 4,593,139; 4,489,215; 4,499,322; 4,495,374; 4,544,784; 4,544,785; 4,547,610; 4,547,611; 4,517,398; 4,544,787; 4,547,608; 4,544,786; 4,568,785; 4,523,049; 4,523,050 and the like.
The conversion of methane to higher molecular weight hydrocarbons in the presence of solids which may contain oxidative synthesizing agents as described in the above patents takes place effectively at elevated temperatures in the range of about 5000.degree. C. to 1200.degree. C. The reaction is strongly exothermic in nature, and in order to properly regulate the reaction and prevent excessive undesirable side reactions, it is necessary to remove the exothermic heat of reaction to avoid an excessive temperature rise, and rapidly lower the temperature of the reaction product mixture.
Problems particular to this conversion of methane include the fact that the reaction temperature is high enough to preclude or bring into serious question the use of many materials normally used in reactor construction.
Fixed bed reactors of the tubular or massive bed configuration have been considered for the reaction. However, such systems have not been satisfactory due to their cost and complexity, to pressure drop and materials of construction problems and to problems of heat removal and effluent quenching. Reference is made, however, to copending U.S. patent application Ser. No. 07/031,496 which discloses an improved thin bed monolithic reactor.
Fluidized solid reactor systems have been considered for the conversion of methane to higher molecular weight hydrocarbons. However, in conventional equipment severe problems of gas and solids backmixing and gas bypassing with resulting selectivity and yield losses have been encountered. Also structural problems are encountered which are compounded by the extreme reaction conditions which are employed and the heat resistant materials which are, of necessity, employed.